Die-off has affected the health of kelp forests and sparked years of scientific detective work
For years, it has been one of the biggest mysteries in marine biology: What is killing the starfish?Since 2013, billions of sea stars, an elegant ocean species commonly known as starfish that are a key part of the environment along the coast of California and other states, have been dying. The animals have suffered from a disease that causes parts of them to shrivel and melt away.In some places 90% of the sea stars died from the gruesome ailment, which is known as “wasting disease.” It has affected more than 20 species of sea stars found in the northeast Pacific Ocean from Alaska to the Baja California peninsula in Mexico, including Monterey Bay, the Sonoma Coast and other parts of the California shoreline, including the most susceptible sunflower sea stars.On Monday researchers at the University of British Columbia and the University of Washington said they have found the culprit: A strain of bacteria called Vibrio pectenicida.The bacteria, a distant cousin of the bacteria that can cause cholera in humans, has been known to harm coral and shellfish. In four years of research, which the scientists published in the journal Nature Ecology and Evolution, the researchers found it causes otherwise healthy sunflower sea stars to melt and die.“It’s just heartbreaking to watch them die,” said co-author Drew Harvell, a University of Washington affiliate professor in the School of Aquatic and Fishery Sciences, and an adjunct faculty member at Stanford University’s Oceans Department. “Sunflower sea stars are enchanting creatures and they’re quite interactive. At feeding time, they will come toward you. If you throw clams to the stars, they can catch them. It’s so gratifying to finally have an answer.”
